First off, you can't use code like
in VBA; actually, I know of no programming language where this would work, although I could be wrong! You have to use
[SqareFeet]>1000 and [SqareFeet]<1500
Also make sure that the spelling of your Field is correct; Access is unforgiving when it comes to things like this! Is it really
or should it be
Also, with eleven possible ranges for square footage, you'll have to nest your IIFs to include them all, and that usually ends up being a hairball! You appear to be planning to use this in the Control Source for your cost Control; I'd move the assignment of the cost to the AfterUpdate event of the Control where you actually enter the square footage, and use the Select Case construct, rather than using If...Then...Else, to do the testing and Value assignment.
Hope this helps!
The problem with making anything foolproof...is that fools are so darn ingenious!
All posts/responses based on Access 2003/2007